OnWednesday，AppleannouncedthatitslatesthandsetwillbeinChinaand21othercountriesonJan13，justthreemonthsafteritwasfirstlaunchedintheUSA．（）A.availableB.acceptableC.affordabl
On Wednesday，Apple announced that its latest handset will be ______ in China and 21other countries on Jan 13，just three months after it was first launched in the USA．（ ）
A. available
B. acceptable
C. affordable
D. measurable
available 可购买的；acceptable 可接受的；affordable 付得起的；measurable 可测量的．根据句意，故选A．
设两个关系R(A,B)和S(A,C)。则下列关系代数表达式中必与等价的是A.ⅡA.B.C(R×S)B 2020-05-23 …
假设有如下两个关系R和S:则以下查询语句:SELECT A,B,C,D,E FROM R,S WHE 2020-05-24 …
假设有如下两个关系R和S:则以下查询语句:SELECT A,B,C,D,E FROM R,S WHE 2020-05-24 …
A.πA,D(σC=D(R×S))B.πA,R,D(σS,C=R,D／(R×S))C.πA,R,D( 2020-05-26 …
A.πA,D(σC=D(R×S))B.πA,R.D(σR.C=S.D(R×S))C.πA,R.D(σ 2020-05-26 …
A.πA,B,C (σB=B(R×S))B.πR.A,R.B,R.C (σR.B=S.B (R×S) 2020-05-26 …
SELECT (52)A.A,R.C,F,GB.A,C,S.B,S.FC.A,C,S.B,S.CD. 2020-05-26 …
(18)A.A, R.C, F, GB.A, C,S.B, S.FC.A, C, S.B,S.CD. 2020-05-26 …
A.πA,D(σC=D(R×S))B.πA,R.D(σS.C=R.D(R×S))C.πA,R.D(σ 2020-05-26 …
关于圆台侧面积公式证明我看了这样一个方法方法2：利用圆锥侧面积公式证明S圆锥侧=πRL设R的母线长 2020-07-25 …